Arrangement of load carrier and lifting mechanism for trucks



July 17, 1951 Y F. sToNER ARRANGEMENT 0F LOAD CARRIER AND LIFTING MECHANISM FOR TRUCKS 9 Sheets-Sheet l Filed July. 12, 1945 n F. sroNER. ARRANGEMENT oF LoAD CARRIER AND LIRTING MECHANISM FOR TRUCKS July 17, 12951 9 Sheets-Sheet 3 `Filed July l2, 1945 I i .WIIT ||llll FRANK STONER.

F sToNER 2,560,608

-ARRNGEMENT ILOAD CARRIER AND LIFTYING ISM FOR TRUCKS July 17, 1951 9 Sheets-Sheet 4 Filed July 12, 1945 1 l INVENTOR. 6 FRANK sToNER.

BY` M July 17, 195] STONER 2,560,608

ARRANGEMENT OF LOAD CARRIER AND LIFTING MECHANISM FOR TRUCKS Filed July 12, 1945 9 Sheets-Sheet 5 FIG. 7a

July 17, 1951 F. sroN-:R I

ARRANGEMENT oF LOAD CARRIE-.R AND LIFTING MEGHANISM FOR TRUCKS Filed July 12, 194s 9 sheets-sheef e FRANK STO'NER.

Jil-ily 'K F. sToNl-:R ARRANGEMENT oF LOAD CARRIER AND LIFTING Filed July 12, 1945 MECHANISM FOR TRUCKS FIG. .1o

9 Sheets-Sheet 7 BYv INVENTOR. FRANK sToNER.V

July 17, 195] F. sroNl-:R 2,560,505

ARRANGEMENT LOAD CARRIER AND LIFTING ME NISM FOR TRUCKS Filed July 12, 1945 9 sheets-sheet lll JNVENTOR FRA N K STONER.

JulyV 17, 1951 F. sToNER 2,560,608 ARRANGEMENT oF LOAD CARRIER AND LIFTING MECHANISM FOR TRUCKS Filed July 12, v1945 9 Sheets-Sheet 9 o lob lob' INVENTOR. FRANK STO NER.

ATTORNEY.

Poema July 1v, 1951 ARRANGEMENT F LOAD CARRIER AND LIFTING MECHANISM FOR TRUCKS Frank Stoner, Lakewood, Ohio, assigner to The Baker-Raulang Company, Cleveland, Ohio, a

corporation of Ohio Application July 12, 1945, Serial No. 4,565

' 3 Claims. l

This invention relates to a. truck provided with a guiding element and having a power propelled steerable traction mechanism, manually controlled by means on the guiding element, Whereby an operative walking at one end of the truck may transport loads from place to place in a ready As later set forth, the truck includes a material handling mechanism. The operative is therefore relieved from the labor of pulling or pushing the truck, as well as the undue physical exertion when traversing inclines, whether the truck is loaded or unloaded.

One object of the invention is to provide an improved truck of this type wherein the control for retarding and/or braking the truck is materially simpliiied, whereby less energy and movement in moving the guiding element is required and a ready and positive control of the truck movement at maximum or reduced speed or stoppage of such movement results.

Another object of the invention is to provide an improved truck of this type having an material handling mechanism for loads and hydraulically operated power means for driving the truck and operang the mechanism.

Another object of the invention is to provide animproved material handling and carrying truck of this type having hydraulic means for driving its traction mechanism and hydraulic means for operating the handling and carrying mechanism vand a single source of fluid supply under pressure,

whereby these means and the fluid supply therefor are simplied in construction and assembly.

Another object of the invention is to provide an improved truck consisting of a tractor unit and a load carrying and lifting unit, the latter having a platform extending rearwardly of the tractor unit and at a low level and Supportedat iis outer end by swingably mounted rollers which are operated by a power mechanism carried by the tractor unit.

A further object of the invention is to provide an improved truck having a material handling mechanism which is capable of engaging skids or double faced pallets in carrying out load transporting operations.

. Other objects of the invention will be apparent to those skilled in the art towhich my invention relates from the following description taken in connection with the accompanying drawings, wherein:

Fig. l is a side elevation of a truck embodying my invention, parts being broken away.

Fig. 2 is a front elevation.

Fig. 3 is a plan view.

(Cl. 25d-2) 2 Fig. 4 is airagmentaryviewgonthelinel-l of Fig. 3, showing the lift in elevated position.

Fig. 5isasei-.tionontheline5---5ofFig 1. 5 Fig. 6 is a fragmentary section on the line 6 6 of Figs. 1 and 7.

Fig. 7 is a section on the line 'I-l of Fig. 6. Fig. 7a is a section on the line 'la-'Ia of Fig. 6. Fig. 8 :is a fragmentarysectionontheline 3 8 of Fig. 3, enlarged.

Fig. 9 is a bottom plan view of the pimp. Fig. 10 is a section on the line lI-Il of Fig. 9. Fig. 11 is a section through the travel valve, on the line I i-II of Fig. 3, enlarged. 15 Fig. 12 is an elevational view of the valve for the lift mechanism. looking toward the leftv of suitably welded or otherwise rigidly connected to provide a rear section la and a front section Ib. the latter preferably having curvilinear side walls supporting therewithin a plate Ib' Vformed with an enlarged opening Ic for a Purpose later referred to. The rear frame section la consists ol' depending side bars 2 to which are rigidly connected spaced angles 2', a front bar 2.1: connecting the side bars and a rear bar 2a, the angles and rear bar serving to movably support a material handling mechanism indicated as an entirety at 3. The upper ends of the bars 2, 21: and 2a are provided with transversely arranged angles 4 on which a battery 5 is molmted. the battery serving to supply current to a motor 6, which is later referred to. The angles I ane connected by tie members la, which are welded to the lower sides thereof and the side bars 2. The battery is preferably enclosed in a housing 51: supported on the rear frame section la on the rear side of an up-standing transverse plate 'I xedly mounted on the frame I when the housing 5r is omitted, the battery may be slid on the angles l transversely of the frame section la into position on the section la or to remove it therefrom, but wherethe housing is employed the battery may bepositioned on or removed from the section la by a crane e ears 5a on the bat- 55 tery 5.

The truck frame I is mounted for translation from place to place on a combined traction and steerable mechanism, (indicated as an entirety at 9), rotatably carried by the front frame section Ib, which mechanism in the present disclosure includes a wheel 9'. and one or more supporting wheels I0, which form part of the material handling mechanism 3. In the present disclosure, for reasons later apparent, I provide two pairs of wheels I (each wheel of each pair being relatively wide), which are mounted on swingable yokes or devices (later referred to) to raise and lower the outer end portion of the load handling mechanism 3. In the form of construction shown the material handling mechanism 3 is movably connected to the frame I, and the wheel 9' and wheels I0 co-operate to support the frame I, when the truck is at rest or is being driven, irrespective of whether the mechanism 3 is raised or lowered and loaded or unloaded.

As shown in Fig. 6, the driving means for the wheel 9' is of the hydraulic rotary type and is incorporated therein and the power supply for the driving means and its valve mechanism are unitarily connected with the mounting for the traction and steerable mechanism to simplify the assembly and insure a direct connection between the power supply and the driving means.

The combined traction and steerable mechanism comprises the following: I I indicates an axle fixedly supported at its opposite ends inarms IIa which are iixed to and depend from a disk I2. The marginal portion of the disk I2 engages a ring bearing I3 of the anti-friction type, provided between the disk and marginal portion of the opening Ic, whereby the mechanism is bodily rotatable about the axis of the bearing I3 for steering the truck when the latter is being power driven or manually moved. The axle I I is formed with ducts I4, I4', extending inwardly from its opposite ends, each duct being connected with a supply duct I4a formed in and extending through the adjacent arm IIa; in this arrangement the duct I4 and the adjacent duct I4a supply iiuid--such as oil-(which supply is under pressure) to the driving means or motor, indicated as an entirety at I5, to drive thel wheel 9' in one direction and the duct I4' and the adjacent I4a supply iuid to the driving means or motor I5 to drive the Wheel in the opposite direction. The hydraulic rotary motor consists of a stator I6 fixed to the axle II and having an outer wall eccentric to the axis of the axle I I, as shown at |61 and a rotor I1 suitably fixed to the rim 9a for thewheel 9', the rim 9e being preferably provided with a tire of the solid rubber type. The rotor I1 and wheel 9' are mounted to rotate on the axle II in the following manner; I8 indicates cup shaped hub members rigidly secured to the opposite ends of the rotor I1 by cap screws I8a. The hub members I8 are interiorly shaped to accommodate suitable anti-friction bearings I9, the inner end of the inner race of each bearing being seated against an annular shoulder provided on the axle II, and its outer end being biased inwardly by a coiled spring Isa interposed between it and the end wall of the adjacent hub member I8. Annular disks 2'0, which are interposed between the rotor I1 and hub members I8 and fixed thereto by the screws Isa, extend inwardly beyond the rotor I1 to engage the inner ends of the outer races for the bearings I! and maintain them in their seats provided on the inner walls of the hub members I8. The stator I6 is mounted between the disks 20, which prevent endwise movement thereof longitudinally 0f the axle.

The inner wall of the rotor I1 is formed with a plurality of cylindrical sockets I1a disposed parallel to and equal distances from the axis of the axle II and each oscillatably supporting therein a pin I'Ia' to 'which is rigidly secured a follower I1b. Each follower extends into the chamber between the rotor I1 and stator I6 and rides the surface of the latter as the rotor I1 rotates. 'I'he inner wall of the rotor I1 is recessed opposite the outer end of each follower, as shown at I1b', to accommodate the swinging movement of the follower as it rides the eccentric portion of the stator I6. Each follower I1b is biased inwardly about the axis of the adjacent pin I1a' by a plunger l1c slidably mounted in an opening I1c' formed in the rotor I1. Each plunger I1c is preferably hollow to form a seat for the inner end of a spring I1d. its outer end abutting a plug I1d' threaded into the outer end portion of the adjacent opening I1c'. As will be observed from Figs. '1 and 1a. I provide two sets of followers Ilb, the followers of each set being uniformly spaced about the axle II and each follower of one set being disposed between two followers of the other set; also, that the followers I1b of one set extend in a clockwise direction and those of the other set extend in a counter-clockwise direction (as viewed in Figs. '1 and 7a). Accordingly, iiuid supplied through ducts Ma, I4 and a port I 4a: formed in and leading through the axle Il and stator I6 and having its outlet at one side of the eccentric ISI will apply high pressure to the followers |1b which extend counter-clockwise to rotate the rotor I1 in the direction indicated by the arrow :r' in Fig. 7, the supplied fluid being discharged on the low pressure side through a port I4e at the opposite side of the eccentric and formed in and leading through the stator I6 and axle II and connected to the Aduct I4' (see Fig. 7a); likewise, fluid supplied through ducts Ila, I4' and port |4e will apply high pressure to the followers I1b which extend clockwise to rotate the rotor I1 in the direction indicated by the arrow :c' in Fig. 7, the supplied fluid being discharged on the low pressure side through the port |41: and ducts I4, I4a. From the foregoing description it will be noted that by controlling the flow of the iiuid, the motor I5 may be driven in either direction. It will be understood that upon the admission of the fiuid through one port to the rotor I1, pressure is initially applied to one active follower I1b and then progressively to the correspondingly positioned followers as the rotor rotates and that this pressure continues until the supplied fiuid is discharged through the other part, whereas the oppositely disposed foilowers I1b will yield in the direction of fluid flow in opposition to the springs I1d to permit the fluid pressure to be maintained on the active followers until it is discharged through the latter port. By preference I provide at opposite sides of the eccentric |61: two ports Mz, I4e, respectively, so that the pressure may be applied to two active followers substantially simultaneously.

The iiuid supply for the motor I5 consists of a tank 2| for holding a supply of fiuid, fixed to the disk I2, a. rotary pump indicated as an entirety at 22, driven by the motor 6, for circulating the iiuid. a valve mechanism indicated as an entirety at 23 for controlling the fluid supply to the ducts I4a and operating means (later referred to) for the valve mechanism 23. The top wall of the tank 2l has secured to it a plate 23' (see Fig. 8), which is provided with an upstanding shaft 23a, in coaxial relation with the axis of the ring bearing I 3 and rotatably mounted in a bearing 24 carried by a collar 24a. The collar 24a is suitably fixed to a base plate 24h which is rigidly secured to a bracket 24e carried by the upper end portion of the wall 1. The upper end portion of the shaft 23a is provided with an annular shoulder 23h and outwardly 'thereof the shaft 23a is provided with screw threads 23e to take a nut 23d, which is tightened through a washer 23e against the shoulder 23h and co-operates with the ring bearing I3 to rotatably support the wheel 9' and motor I5 and parts carried by the disk I2 in the frame section Ib and maintain them against vertical movement relative to the latter. The casing for the pump 22 is bolted directly to the side wall of the tank and preferably consists of an upper section 22a, a lower section 22h, an annular side section 22e and bearing supporting members 22d spaced by the side section 22e and interposed therebetween the latter and the upper and lower casing sections. The casing sections are assembled in alined relation by dowel pins 22g and secured together by bolts 22g. The members 22d support bearings (preferably of the anti-friction type) for the shafts 22e for suitable impellers 22j, one of said shafts being extended upwardly and directly coupled to the shaft of the motor 6. The upper casing section22a. is formed with a recess 22a' in registry with an opening in the side wall of the tank 2| and connected to a duct 22x leading into one side of the pump chamber, whereas the side s ection 22c is formed with an outlet 22e', remote from the outlet end of the duct 221, connected to a pipe 22e, which leads to the valve mechanism 23, as shown in Figs. 1 and 2. The upper pump section preferably terminates in an inverted bellshaped wall 229:' which is secured to the lower end of the motor 6.

The valve mechanism 23 is provided with two separately operating valves, whereby the fluid may be supplied to the motor I5 to drive the Wheel 9' in either direction, and is constructed to operate as follows: when the valve elements are in neutral or normal position, the fluid is by-passed through the valve casing and is returned to the tank 2|, this return preferably being through a valve mechanism 25 for controlling the material handling mechanism 3 to operate the latter when the truck is at rest,` whereby separate fluid connections between the pump 22, the valve mechanism 25 and tank 2| are eliminated, since no occasion would arise for driving the traction wheel 9 and simultaneously operating the mechanism 3 to raise it. The casing for the valve mechanism 23 is mounted on the front wall of the tank 2| and preferably formed in sections and provided therein with flow channels as follows: 26 indicates a transverse channel having at its upper end an extended channel 26a parallel to the upper portion of the channel 26. 21 indicates a supplemental transverse channel. 28 indicates an outlet channel leading to an outlet 28a, which is connected to a. pipe 29. The pipe 29 is connected to the valve mechanism 25, from which the fluid is returned to the tank 2| or utilized to operate the load handling mecha- A nected through outlets to pipes 3|', 32', respec-A tively, the pipe 3| being connected to the duct 6 lIla which is connected with the duct I4', to drive the wheel 9' in the direction to eil'ect forward travel of the truck when one valve element (indicated as an entirety at V33) is operated and the pipe 32 being connected to the duct I4a. which is connected to the duct I4 to drive the wheel 9' in the opposite or rearward direction when another valve element (indicated as an entirety at 33') is operated. As will be observed, when the fluid is supplied through the pipe 3| to the motor I5 for forward truck travel, the fluid in the ducts I4', |4a, is forced by the motor back through pipe 32 for return flow to the tank 2| and when the fluid is supplied through pipe 32 to the motor I5 for rearward truck travel, the fluid in the ducts I4, |4a, is forced by the motor` back through pipe 3|' for return flow to the tank 2|, the valve mechanism 23 being constructed, as will later be set forth, to provide for this return fluid flow to thus eliminate separate flow connections from the motor I5 to the tank 2|. The channel 3| is provided with branch channels 3 Ia, 3 I b, 3 Ic, whereas the channel 32 is provided with branch channels 32a, 32h, 32e.. 34 indicates a return ilow channel for the fluid having an outlet 34a which registers with an opening formed in the adjacent wall of the tank 2|. 35 indicatesa longitudinally extending opening in line with and connected with the'channels 21, 26a, 26, 3|c, 3|b, 34'and 3|a, the wall of the opening 35, between certain of said branch' channels, forming aV guide for the valve element 33 and flow ports for the fluid between said channels, dependent upon the position of the valve element 33. 36 indicates a longitudinally extending opening in line with and connected with the channels 28, 21, 26, 32o, 32h, 34, 32u-, the wall of the opening 3S, between certain of said branch channels, forming a guide for the valve element 33' and flow ports between said channels, dependent upon the position of the valve element 33'. The outer end of the valve element 33 when in neutral position (see Fig. 1l) terminates in the channel 3|b, so as to permit fluid flow from the pipe 3 I through the channels 3|a, 3|, 3Ib. and opening 35 to the channel 34, but when the valve element 33 is operated (as later set forth toward the left as viewed in Fig. 11), the opening 35 between the channels 3Ib, 34, is closed. As shown, portions of the valve element 33 are reduced to form annular recesses 33a., 33a the opposite outer ends walls of which provide cut-offs 33h, 33h'. Also, as shown, portions of the valve element 33' are reduced to form annular recesses 33e, 33e', the opposite outer end walls of which provide cut-offs 33d, 33d', and the outer end of the valve element 33', when in neutral position, terminates in the channel 32h so as to permit fluid flow from the pipe 32 through the channels 32a, 32, 32h and opening 36 to the channel 34, but when the valve element 33' is operated (as later set forth toward the left as viewed in Fig. 1l) the opening 36 between the channels 32h, 34, is closed.

When both valve elements 33, 33', are in neutral position (as shown in Fig. l1) and motor 6 Ais operating to drive the pump 22 the fluid from the supply pipe 22a flows through channel 26a, recess 33a', channel 21, recess 33e', channel 28 and pipe 29 and returns to the tank 2 I, as already set forth. If valve element 33 is operated, cut-off 33h' closes the channel 26a, cut-olf 33h opens the connection between the channels 26, 3 Ic, and

the outer end of the valve element closes the connections between thechannel 3| b and channel 3|, so that the fluid from supply pipe 222 flows i nel 34 and opening 34a to the tank 2|.

through channel 26, recess 33a, channel 3Ic, channel 3| and channel 3Ia, to the pipe 3|' to one side of the motor I and from the other side of the motor through pipe 32', channel 32a, channel 32, channel 32h, opening 36, channel 34 and opening 34a to the tank 2I; and if the valve element 33 is operated, the cut-01T 33d' closes the channel 21, cut-olf 33d opens the connections between the channel 26 and channel 32e and the outer end of the valve element closes the connections between the channel 32h and channel 34, so that the fluid from the supply pipe 22a ows through the channel 26, recess 33e, channel 32e, channel 32, channel 32a and pipe 32 to the opposite side of the motor I5 and from the first mentioned side thereof through pipe 3l', channel 4Ia, channel 3I, channel 3Ib, opening 35, chan- If both valve elements 33, 33', are simultaneously operated the fluid will be supplied to both sides of the motor I5 through the respective channels as above Set forth, the eiect of which is to stop it and hence stop the wheel 9'; accordingly, when the truck is in motion, due to operation of one of the valve elements, the other valve element may be operated and thus provide uid pressure from the supply pipe 22e in opposition to the return flow of fluid from the motor I5, the effect of which is to retard the operation of the motor and to slow down the rotation of the wheel 9 and bring the motor to a stop, if desired. It will thus be observed that when the truck is being driven in either direction, the valve elements 33, 33', may be operated to increase or decrease the speed of the truck as well as provide a braking effect whether the truck is traversing a level or inclined surface. In this arrangement mechanical braking elements for the wheel or motor and a separate control therefor are eliminated. Due to the fact that the fluid system and motor rotor I1 are completely lled with fluid at all times, operation of either valve element 33, 33', insures quick starting, and operation of both elements insures ready braking and stoppage of the motor I5.

31, 31', indicate as entireties relief valve means mounted in the outer ends of the openings 35, 36, respectively, to relieve excessive pressure which may exist in the fluid system at any time. As these valve means are similar in construction, one (valve means 31) only will be referred to. The valve means 31 consists of a sealing member 31a seated in the opening 35 and formed with a through opening, the inner end of which serves as a seat for a valve element 31b. The valve element 31h is provided with a hollow shank 31e which slidably ts the opening through the element 31a. The outer end of the shank 31e is open to admit uid thereinto from the channel 3 Ia and its side Wall is formed with a port (preferably two ports, in disalinement longitudinally) to connect the opening in the shank with the channel 34 when the valve element 31b is unseated. The valve element 31h is normally held in engagement with its seat by an expansion spring 38 interposed between it and the valve element 33, the outer end portion of which is formed with an inwardly extending recess 33:1: to accommodate the spring and permit a long spring to be employed. In this arrangement, each spring 38 is put under compression when the adjacent valve element 33 or 33 is operated to prevent operation of the relief valve when the fluid is being supplied to the motor I5 through the pipe 3 I or pipe 31.

of a single load carrying member for loads, but by preference such support consists of spaced, xedly related parallel load carrying members 3a, 3a, which may engage with and raise a double faced pallet, indicated as an entirety at A. aS shown in Figs. 14 and 15. Each member 3a consists of a pair of channels or side bars 3b on which a platform 3c is xedly mounted. The outer side bar, at its inner end portion, is related face to face with and rigidly secured to the adjacent side 39 of a U-member 39a, whereas the inner side bar, at its inner end, is rigidly secured to the base portion of the U-member 39a. Each side 39 of the U-member 39a is rigidly connected to the base portion thereof by a base plate 40. The load carrying members 3a, U-member 39a and base plates 40 are movably supported for vertical movement as a unitary assembly by pairs of front and rear parallel levers or bell-cranks 4I, 4Ia, each pair thereof being fulcrumed on a shaft 42, the opposite ends of which are mounted on the depending sections of the angles 2'. The inner end of each front bell-crank 4I is pivotally mounted on a standard 43 xed to an angle 43x carried by the adjacent plate 40, whereas the inner end of each rear bell-crank 4Ia is pivotally mounted on a standard 43a fixed to the base portion of the U-member 39a. The outer ends of the bell-cranks 4I, 4Ia, of each pair are connected together by a link 44 and the outer ends of the front bell-cranks 4I, 4Ia, are pivotally connected to a cross-head 44a carried by the outer end of a piston rod 45. 'Ihe inner end of the piston rod 45 is provided with a piston 45a reciprocatablc in a cylinder 46, the outer end of which is pivotally mounted on a bracket 46a fixed to the wall 2a. of the frame section la. The rear end of the cylinder 46 is provided with an inlet to which a fluid supply pipe 41 is connected, the opposite end of the pipe being connected through the collar 24a. and shaft 23a to the valve mechanism 25 (as later set forth). The supply of fluid to the cylinder 46 serves to operate the piston 45a outwardly (toward the left as viewed in Figs. l, 3 and 4), which movement swings the bell-cranks 4I, 4Ia, about their fulcrums and raises the load carrying members 3a and through a linkage hereinafter referred to simultaneously swings the yoke' (which carries the wheels IIJ) about its shaft, as later set forth, the effect of which is to raise the outer ends of the members 3a in co-operative relation with the movement of the bell-cranks 4I, 4Ia (see Fig. 4), so as to maintain the members 3a horizontal during movement thereof as well as relieve undue strains on the frame I and bell-cranks 4I, 4Ia. Movement of the piston 45a inwardly is effected by the gravitation of the members 3a by control of the valve mechanism 25, as later set forth, the linkage and bell-cranks co-operatively serving to maintain the members 3 horizontal during downward movement of the latter. Due to this coordinated movement of the bell-cranks 4I, 4Ia, and wheels I0, danger of tipping the load or causing it to slide on the members 3a is avoided. v

To provide for the swinging movement-of the wheels I0, the shaft 48 for each pair thereof is supported in the outer end of a yoke 48a. The yoke 48a. is swingably mounted at its inner end on a shaft 49, the latter being supported at its opposite ends in the side bars 3b of the adjacent member 3a. The yoke 48a for each pair of wheels I0 preferably consists of side elements and an intermediate element 48a', to which the outer The load handling mechanism 3 may consist 75 end of a pull rod 49a (which forms a part of the 9 linkage already referred to) is pivotally connected. The inner bifurcated end of the pull rod 45a is movably supported on pads 49h carried by the adjacent plate In and pivotally connected through a link I! to the outer end of an arm 5| xed to and depending from the horizontal section o the adjacent angle 2' (see Fig. 5). When the members 3a are rased, as above set forth, the inner end o each rod 45a is moved upwardly relative to the arm 5l, due to the engagement of its inner bifurcated end with the pads 49h, so that the link 50 between the arm 5l and rod 49a exerts a pull on the rod 49a and moves it endwise toward the left (as viewed in Figs. 1, 3 and 4) and operates to swing the yoke (8a to the position shown in Fig. 4. AWhen the load handling mechanism 3 is in its lower or normal position, the yoke 48a is held in an inclined position (see Fig. l) by the arm 5l, link 50 and rod 49a, but when the latter is moved endwise as above set forth, and the yoke 48a is swung about its shaft I9, it re-acts between the ground and adjacent member 3e to raise the latter, as shown in Fig. 4. m this movement of the yoke 48a is effected by the movement of the inner end of the adjacent member 3a, the yoke serves to support and maintain the member 3a in horizontal position during this movement and when the member is held in elevated position. Due to the linkage connections between the yokes 48a and frame section la, it will be observed that in either position of the yokes, the wheels l5 co-operate with the wheel 9 to support the frame l and provide for translation oi the latter from place to place. The inner bifurcated end of each rod 49a is preferably provided with rollers 49a: for rolling on the pads I Sb during endwise reciprocatable movement of the rod. As shown in Figs. 1 and 4, the shafts for the rollers i993 are extended and project through and traverse elongated slots formed in angles I9', which are xed to the plates 4u, the engagement of the shafts with the walls of the slots serving to connect the inner ends of the rods 49a to the plates 60 to insure movement thereof downwardly with the load 'handling mechanism 3 and endwise movement Due to the fact that the truck is guided or c steered by the operator through the instrumentality of a manually operated element, indicated as an entirety at 52, the controls (later referred to) for the motor l5 and material handling, mechanism 3 and the fluid supply tank 2l motor 6 and duid circulating pump 22 are mounted on 10 lng 56, whichisinlinewiththerecessiiandis connected to that section of the pipe l1 leading to the cylinder 46, whereby iiuid ilow between the valve 25 and cylinder I6 is provided :for while permitting steering of the wheel B. 1

The valve mechanism 25 comprises the following: 25a indicates the valve housing. preferably bolted to the side wall of the tank 2l by screws 25a', and formed to provide a plunger bore 25h preferably extending therethrough from end to end. A tapped uid pressure outlet and return port 25e to which the pipe 41 is connected, extends inwardly from one side of the housing 25a, intersecting the plunger bore 25h and completely surrounding the plunger 25d within the bore. whereas the opposite side of the housing 25a is formed with a pressure inlet passage and port 1I), to which the pipe 29 is connected, surrounding the housing bore 25h for the purpose 4of introducing pressure hydraulic fluid to the control valve. The ports 25e and 10 are adjacent each other and positioned approximately midway of the length of the housing bore 25h, which bore terminates at its upper end in an enlarged discharge passage 1|, which is connected through an opening lla with the tank 2l.

The chambered valve housing 25a includes at its lower end an enlarged passage or port 12 surrounding the valve bore 25h in communication with the tank 2 I. The upper end of the bore 25h, beyond which the plunger 25d never eztends, is closed by a hollow screw cap 51 sealed by a gasket 51'. A coiled, centering or neutralizing spring 58 surrounds the valve plunger 25d within the discharge passage 1| and is secured at one end by a threaded plug and cap 60 tapped into the adiacent end of the hollow valve plunger. While the head of plug 60 ts loosely within the hollow screw'cap 51, the inwardly extending end of the latter serves as a seat for the spring 58 in the neutral position illustrated in Fig. 13. The valve plunger 25d is formed to provide also a shouldered land portion 62 for receiving the neutralizing spring 58 and the valve housing 25a is shaped to form a countersunk seat for the inner end of the spring 58. Washers 155 may be used at the opposite ends oi the spring 5'8 to provide continuous seating areas of good width for either pushing or, in cooperation with the cap 51 of housing 25a, holding the corresponding end of spring 58 as the plunger 25d is moved relative to its neutral position. In view of the the rotatable `disk l2, the'uid connection 41 to and from the cylinder 4E is preferably .provided in the joint or bearing elements 23a, 24a. As shown in Fig. 8, the shaft 23a. is formed with a duct 53 closed at its upper end by a plug 53a. At its lower end, below the bracket Zic, the duct 53 is provided with a lateral port 54 to which that section of the pipe 41, leading from the valve 25, is connected. The upper portion of the shaft 23a, intermediate the hearing 24 and shoulder 23h, is formed with an annular recess 55, which is connected by a plurality of ports 55a. with the duct 53, whereas the collar 21a is formed with an`openpossibility of leakage endwise ofthe hollow valve plunger, its threaded plug 6l! is provided with a resilient seal ring 66 cooperating with the interior of the plunger.

The upper end of the hollow plunger 25d carries a check valve means, which preferably comprise a relatively light check valve spring 58 bearingr at one end on the end of plug GD and at the other upon a check member in the form of a ball 10 seating across the smaller intermediate passage portion 12' of the valve plunger 25d, and controlling the passage of hydraulic pressure uid from an immediately adjacent side delivery port 14.

In like manner, the lower end of the hollow valve plunger 25d is tapped to receive the threaded end 16 of a lug 18 and is provided with a resilient sealing ring 8U acting between the interior of the valve plunger and the end 15. As later set forth the lug 1B is pivotally connected to a control element for operation by the operative. A relatively heavy relief valve spring B2 acts against the threaded end 1B and a relief 1 l valve member 84 preferably in the form of a ball for the sake of simplicity and economy. The ball member 84 seats over the adjacent end of a reduced port 86 of the plunger bore to close this end of the bore at a point slightly inward of side delivery ports 88.

Between the longitudinally spaced side delivery port 14 and side delivery ports 8B, adjacent the respective check valve means, is an inlet and outlet side delivery port 90 controlled only by the passage or unported portions of the plunger bore 86.

It will be appreciated that the side delivery ports 14, 88, and 90 may be of any desired shape and may constitute outwardly opening slots in the valve plunger 25d, but preferably consist of circumferentially spaced series of moderate sized drilled openings of circular shape at each of these places.

The side delivery relief port or ports 88 lie within an extended groove part 92 of plunger 25d, the length of this groove part being sufficient to provide a by-pass between the hydraulic fluidpressure inlet port and the combination bypass and relief port 12 when the plunger 25d is in its neutral position.

The operation of the control valve will now be explained with reference to Fig. 13. The spring 58, which has one of its ends in abutment with -the Valve housing 25a and the other with the cap 51, normally maintains the valve plunger 25d in the neutral position as illustrated. At this time, the unpassaged or unintersected portions of the valve bore 25h effectively block both the side delivery ports 14 and 90, and the ball member 84 of the relief valve means is not exposed to any hydraulic fluid pressure. Note is also made that the grooved portion 92 of the valve plunger 25d affords a good sized ring shaped by-pass opening from the pressure inlet passage 10 directly to the enlarged hydraulic fluid port 12 which is in open communication with the reservoir tank 2|. In this neutral position of the valve plunger 25d a free fluid by-pass is provided from the pump 22 through valve 23, the pipe 29, port 10, the plunger groove 92 and out the combination by-pass and relief port 12.

By a downward movement of the valve plunger 25d the intermediate side delivery ports 90 communicate with the hydraulic fluid pressure supply port 10 and groove 92 is closed. Pressure hydrauby the relief valve ball 84 and constrained to flow through the valve plunger where it unseats the lightly spring-pressed check ball 10' and discharges into the hydraulic fluid outlet port 25e which has, at the same time, been placed in hydraulic fluid communication with the side delivery ports 14.

When the valve plunger 25d is moved upwardly beyond its neutral position, the side delivery ports 98 are moved into registry with the tapped opening 25e and the ports 14 are moved into communication with the passage 1|. Again being blocked by the superior resistance of the relief valve ball member 84, the hydraulic fluid returned from the hydraulic cylinder 46 will unseat the check valve ball 10' and discharge through the side delivery ports 14 to the passage 1I whence the hydraulic fluid is returned to the tank 2| through the outlet 1|a.

From the foregoing description it will be observed that when the valve plunger 25d is moved downwardly fluid is supplied from pipe 29 and flows through the plunger to pipe 41 and through -lic fluid thus introduced is blocked at one end the latter to the cylinder 46 to operate the ma.d terial handling mechanism 3 upwardly and that when the valve plunger 25d is moved upwardly (beyond its neutral" position) fluid return flow from the cylinder 46 is through the pipe 41 and valve plunger 25d to the passage 1I and through the outlet 1Ia to the tank 2 I, to permit lowering of the material handling mechanism 3. It will also be observed that when the material handling mechanism 3 is raised, it may be retained in such position merely by moving the valve plunger 25d to neutral" position, thereby closing off return flow of the fluid through pipe 41 and effecting fluid flow from pipe 29 to passage 12 and back to the tank 2 I.

In the normal operation of the control valve 25 to supply fluid to the cylinder 46, the relief valve means will function only to block one end of the hollow control valve plunger 25d through the medium of the ball member 84. In such operetion the relief valve means will function to relieve excessive hydraulic fluid pressure and return it to the reservoir tank 2|, in the event that the material handling mechanism 3 should meet with unusual resistance or the then open part of the hydraulic fluid circuit should be pressure blocked in some other manner. Also, in the lowering of the material handling mechanism 3 the check valve means having the ball 1D and responsive to a lesser hydraulic fluid pressure, is effective in relieving pressure produced by return of hydraulic fluid from the hydraulic flow port 25c. It would, however, be possible for the relief valve means to function selectively during the downward movement of the material handling mechanism 3 should there be an abnormal surge of returned hydraulic fluid of such a pressure and volume that the check valve means could not handle all of the flow.

The arms IIa depend from a bracket fixed to the disk I2 and are provided with integral skirts I|b which are related to side skirts IIb' depending from a bracket IIb" also fixed to the disk |2. The skirts IIb' terminate in a pair of spaced, parallelly related outwardly extending supports |Ic. The guide or steering element 52 consists of a tubular member 93, a loop shaped member 93a at its lower end and a housing member 93h at its upper end. The side walls of the loop shaped member 93a are fulcrumed on and between the supports IIc (see Fig. 2), whereby the steering element 52 may be bodily swung forwardly into convenient position to be grasped by the operative for guiding and controlling the movement of the truck. The lower end of the member 93a is pivotally connected to the outer end of a rod 84; the inner end portion of the rod is slidable in a fitting 94a suitably mounted on a rock shaft which is supported in the skirts IIb'. A spring 94h coiled around the rod 94 and interposed between the fitting 94a and the knuckle at the outer end of the rod 94 normally tends to swing the element 52 upwardly and maintain it in vertical position as shown in Fig. l. The construction of the steering element 52 provides for the mounting of the controlling devices 95, 95a, for the valve mechanism 23 and a controlling device 96 for the valve mechanism 25 at or adjacent its outer end, whereby the operation of the rotary motor I5 and material handling mechanism 3 may be effected by the operative independently of the position of the steering element, so that bodily movement thereof is not required to operate or stop the motor I5 and the mechanism 3. The controlling devices 95, 95a, consist r 13 of handles rotatably mounted in-the side walls of the housing member 93h (preferably in axial relation) and extending laterally therefrom. 'I'he inner end of each handle is provided with an arm 93e, the outer end of which is pivotally connected to the upper end of a rod 91. 'I'he lower end of the rod 91', which is connected to :the handle 95a, is pivotally connected to the outer end of a bell-crank 91a, which is mounted on the adjacentskirt IIb', and the bell-crank 91a is pivotally connected to the outer end of a link 91h which in turn is connected to the valve element 33. Accordingly. by rotation of the handle 95a counter-clockwise, the valve element 33 is operated toward the left (as viewed in Fig. 11) to supply fluid to the motor I5, as already set forth. 'I'he lower end of the rod 91, which is connected to the handle 95, is pivotally connected to the outer end of a bell-crank 91a', mounted on the adjacent skirt IIb', the inner end of the bellcrank being pivotally connected to a link 91h', which in turn is connected to the valve element 33'; accordingly, by rotation of the handle 95 counter-clockwise the valve element 33 is operated toward Ithe left (as viewed in Fig. 11) to supply fluid to the motor I5, as already set forth.

As shown in Fig. 11, each link 91h, 91h', is pivotally connected to a thrust element 91.12 threaded in the outer end portion of the adjacent valve element and locked by a nut 91x, whereby the operating connections between each handle 95, 95a, and the adjacent valve element may be adjusted to insure accurate operation of the latter.

The controlling element 96 consists of a handle pivotally mounted on a bracket 96a carried by the steering element 52 and provided with an arm 95h pivotally connected to the upper end of a rod 91e. The lower end of the rod 91e is pivotally connected to the outer end o'f a bell-crank 98 (the axis of the pivot for the lower end of the rod 91e being in line with the axis on which the element 52 swings) fulcrumed on a stud shaft carried by the adjacent skirt IIb'. The inner end 98a of the bell-crank 98 is pivotally connected to the outer end of a link 91e which is pivotally connected to the valve element or plunger 25d for the valve mechanism 25 for controlling the latter.

To permit the load carrying members 3a, 3a, to be projected within a double faced pallet A, as shown in Figs. 14 and 15, I provide in each member a roller Ia (preferably two rollers I0a in endwise relation) inwardly of the yoke 48a and a pair of rollers I0b, I0b, outwardly of the wheels I0 and'disposed side by side. Each roller |0a loosely rotates on a shaft I0a. The opposite ends of the shaft |0a are supported in plates |0c which are xed to a pair of transverse tie elements |0c' suitably secured to the inner and outer side members of the adjacent load carrying member 3a. 'I'he rollers |0b, I0b, loosely rotate on shafts I0d supported in a pair of longitudinally disposed plates I0e, which are secured at their inner ends to a transverse tie member I0e' supported between the adjacent side bars 3b and secured at their outer ends to the end wall 3b' for the side bars 3b. It will be observed that the rollers |0a are supported above the ground or surface, when the load handling mechanism 3 is in its lower or normal position (see Fig. 1) and the shafts Ind are mounted on the members 3a in a plane above that of the shafts I0a for the rollers |0a and that the diameter of the roller I 0b' is less than that of the roller |0b. In this arrangement, in moving the truck to project the load carrying members 3a into the pallet A in load raising position, the outer roller I0b' is capable of riding the outer or leading edge of the lower cross member a of the pallet A and to slightly raise the members 3a so that the rollers I0b and |0a can ride this cross member and roll on the inner cross members a' until the far end of the pallet A is reached, as shown in Fig. 14, thereby positioning the wheels |0 above the opening between the cross members a' and a" ofthe pallet. When the members 3a have been positioned as shown, the load handling mechanism 3 is operated by supplying uid to the cylinder 46, such operation serving to endwise move the rods 49a and eifect a downward swinging movement of the yokes 48a. In the initial movement of the yokes 48a the wheels I0 engage the ground or surface, which then operates as an abutment, so that this swinging movement of the inner end of the yokes serves to raise the load carrying members 3a and any load thereon as shown in Fig. l5. By holding the mechanism 3 in elevated position, by control of the valveA mechanism 25 i as already set forth), the truck may be driven to the lo`cation of delivery and then the mechanism 3 is lowered to engage the pallet A with the ground or surface, following which the truck may be driven to remove the members 3a from the pallet A.

99 indicates a casing or housing extending around the parts mounted on the disk I2. 99a, 99a', indicate hoods fitting over the casing 99 and battery housing 5m, the hoods being hinged together.

From the foregoing description it will be observed that the pressure fluid system provides for the circulation of the lfluid by continuous operation of the electric motor 6 to drive the pump 22 and return thereof to the tank 2| duringthe periods when the truck is not being driven or the load handling mechanism 3 is in either lowered or elevated position. This operation may be carried out by providing a suitable switch to close the motor circuit through a' contactor |09.

, I prefer however to maintain the electric motor 0 at rest during these periods and to automatically close the circuit to the motor 6 and drive it each time either valve mechanism 23 or 25 is operated. In this preferred arrangement I provide a switch IOI adjacent to each valve plunger 33, 33', (see Fig. l-these switches for valve plungers 33, 33', shown dagrammatically in Fig. 16), so that when either thereof is operated to supply fluid pressure to the motor I5, the adjacent circuit |02 will operate the contactor |00 to close the motor circuit |03 for the motor S. Each switch |0| consists of suitable contacts in a housing and a resilient switch arm |0| normally disengaged from the contacts, the outer end portion of the arm being disposed in the path of movement of a collar |04 Xed to the adjacent valve plunger 33 by the nut 911:", so that 'operation of the plunger will swing the arm IOI inwardly and close the circuit |02. The corresponding switch, indicatedlat |05 (see Fig. l2), for the valve plunger 25d of valve mechanism 25, is provided with a resilient contact closing arm |06, having on its outer end a roller |06a, arranged to be operated by a cam |01 xed to the valve plunger 25d when the latter is moved downwardly, such operation serving to close the circuit |08 and operate the contactor |00 In the arrangements above described, economical use of the current supplied by the battery 5 results. siem the electric motor 6 is driven only when fluid' pressure is required and since the uid system remains at all times illed with iiuid, no delay occurs in operating the motor I5 or load handling mechanism 3 upon operation of the valve mechanisms which control the iiuid supply therefor.

To those skilled in the art to which my invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention, My disclosures and the description herein are purely illustrative and are not intended tobe in any sense limiting.

What I claim is:

1, A truck comprising a traction and steerable unitvconsicting ef front and rear frame sections, an elevating load carrier unit the inner end portion of which extends inwardly into overlapping relation to said rear frame section, a support rotatably mounted on said front frame section,

between said rod and the other corresponding arms of said belleranks,"a hydraulic supply system having valve controlled connections to one' end of said cylinder, and a device connected to the said wheel support for rotating it to steer said wheel. l

2. A truck comprisinga traction and steerable unit and a load carrier unit, said first mentioned unit consisting of front and rear frame sections, said front frame section having a horizontal wall formed with an opening, a disk rotatably mounted in said opening and a traction mechanism mounted on the lower side of said disk and consisting of a wheel and a mechanism for driving said wheel, a pair of wheels below the outer end portion of said carrier unit and co-operating with said tractionv wheel to support said units, the inner end portion of said carrier unit extending inwardly into overlapping relation to the rear section of said first mentioned unit, spaced parallel operating levers between and connected to said inner end portion of the carrier unit and the rear frame section of said iirst mentioned unit for connecting said units together and for` raising said carrier unit vertically, a hydraulic systtem including piston-cylinder. elements connected thereto, said piston-cylinder elements being disposed horizontally between said spaced levers and mounted on the rear frame section of said rst'mentioned unit and operatively connected to said levers, and an element connected to-said disk for rotating it to steer said truck during translation thereof.

3. A truck comprising a traction and steerable unit and .aload carrier unit, said first mentioned unit consisting of front and rear frame sections. said front frame section having a horizontal wall formed with an opening, a disk rotatably mounted in said opening and a traction mechanism mounted on the lower side of said disk and consisting of a Wheel and mechanism for driving said wheel, a pair of Wheels below the outer end portion of said carrier unit and cofoperatimrs with said traction wheel to support said units, the inner end portion of said carrier unit extending inwardly into overlapping relation to the rear section of said first mentioned unit, spaced supports depending from said rear frame section. spaced pairs of parallel operating levers mounted on said supports, corresponding ends of said levers being connected to said inner end portion of the carrier unit for connecting the latter and said rear frame section of said first mentioned unit together and for raising said carrier unit vertically, a hydraulic system including pistoncylinder elements connected thereto, said pistoncylinder elements being disposed horizontally between said spaced pairs of levers and mounted on the rear frame section of said first mentioned unit and operatively connected to the opposite corresponding ends of said levers, and an element connected to said disk for rotating it to steer said truck during translation thereof.

FRANK STONER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

